The present invention relates generally to elevator installations and, in particular, to a fireproof door for an elevator shaft.
The German patent document DE-A1 25 12 536 discloses a box-like elevator shaft door, in which cooling air feed openings are provided in the lower region of the metal door cover plate at the shaft side and cooling air outlet openings are provided in the upper region of the same. Thereby, the metal door cover plate at the lobby side is cooled uniformly and the metal door cover plate at the shaft side is protected against excess heating.
The French patent document FR-A1 2 610 311 discloses an elevator shaft door which has a frame and which serves as a carrier for a respective insulating panels arranged at the lobby side and at the shaft side. The frame itself is filled with an insulating mat. A fire resistance of two hours is achieved with this door construction.
A disadvantage of the known fireproof shaft doors is that they do not meet the more severe regulations of certain countries in respect of the permitted temperature gradient between the fire side and cool side.